Your link takes me to this:
??
Btw, what LMN8R’s tiny hard to see map told me was that the first branching into a new area in the bad see DLC actually is in the very first level! No wonder I never found it naturally.
So this weekend I kept looking in the first level until I found it!
I got through that area, but the next area killed me with a vengeance. I don’t know if the game itself has become harder or my skills have atrophied or what, but it’s hard!